Britishcar

Please put me down for 1. Thank you!

Thanks! As far as retrobrite goes, the case had absolutely no "burn." I think I should name it Gollum since it seemed to spend so much time in a filthy dark place out of the sun. I also agree about being too abrasive on the case but toothpaste and the magic sponge both worked very well. As far as water on motherboards--no problem. Don't soak them overnight or anything but lots of running hot water (use rubber gloves for your hands) and dishwashing soap. Then give it a day or two to dry before applying power and your components will look brand new.

ACML, great question about cleaning materials. Remember, I had to really attack this poor thing as the filth was old and deep. Motherboard, PCB's in general: hot running water (under the sink) with spashes of Dawn dishwashing soap. A soft toothbrush to get around some components where the dirt had really settled. Rinse, rinse, rinse to get the soap off. Aluminum chassis: hot running water (under the sink) with spashes of Dawn dishwashing soap and a toothbrush with toothpaste on tougher areas. Had to resort to a small flathead screwdriver on some of the crusty hard water deposits. Keyboard keys: removed each one and soaked over night in (initially) hot water with dishwashing soap. Next day, wiped each individually with a cloth towel until I got a good shine. Keyboard substructure: Hot running water, dishwashing soap, then when dry, contact cleaner on the connections. Case and plastics: hot running water, dishwashing soap, toothbrush with lots of toothpaste. But the most effective thing was a Mr. Clean "magic sponge." Rinse, repeat. Resorted to wooden toothpicks with alcohol to get ground in stains out of the plastic grain. spookt: Yes! That is a SIO2USB from Germany. I love that device! Portable and flexible and every known piece of software on one USB key. Picky about its ATR format, though.

DrVenkman, you were indeed right! I was so positive that every connection was sparkling that I got lost in the weeds and began to ignore that simple answer as a possible source of the problem. And yes, I pulled that Amdek right out of her retail box in the early 80's and she's still color-saturated and tack sharp today (with chroma/luma separation)! kheller2, no, no good "before" photos. I really should have done that. The way she looks now involved tooth brush, tooth paste, rubbing sponges, contact cleaner, dish soap and lots and lots of very hot water. There were some purplish-black deep stains sort of "frozen" in the fine grain of the outer casing that nothing would pick up. I finally had to resort to a wooden toothpick dipped in alcohol which I poked and twisted into virtually each super tiny grain of the affected area until the end of the toothpick would grow dark and the case slowly, slowly would give up the stain in that area. The actual dirt, hair, and unidentifiable long dead insect parts washed away fairly quickly but some of that deep dirt...whew! But...the results were great. And it was oddly entertaining. If I end up doing some similar, I'll photo document it similar to a good car restoration series of photos.

kheller2, thank you for the schematic. Kyle22 and ClausB and everyone! Thank you both for the informative debate and all of your help on this journey. Kyle22, you're correct, in my ignorance, I was not aware that Z103 pin 3 has nothing to do with R128. I was probing for differences of any kind between a working motherboard and this one but the results wouldn't really have been very meaningful. And...I now feel that I must disappoint everyone who has been so helpful on this thread since...the old girl started working on her own suddenly and without any warning whatsoever. I can only attribute it to her original filthy condition. From right out of the box her disgusting (trust me, I've never seen anything like it) keyboard and PCB's refused to acknowledge keystrokes. Subsequently, every part of her was scrubbed and blasted clean with contact cleaner, etc. and still she refused to recognize her (or any) keyboard. Then suddenly, this morning, on the workbench, she began to acknowledge keystrokes, likely for the first time in decades. The only explanation I can come up with is from ClausB's original thoughts that perhaps some non-visible piece of remaining dirt somewhere was the culprit. My best guess is that this is likely the case and that all of my pulling and reseating of POKEY and the 4051's, all my probing around, and the seating and reseating of the keyboard connector finally allowed the juice to flow somewhere where it wasn't before. So...perhaps three lessons here. One, you cannot visually trust a pressed (non-soldered) connection to truly connect even though you have cleaned the hell out of it without really confirming true continuity. Second, Atari really built the hell out of these things back in the early 80's. This machine looked like it had been retrieved from a pirate ship at the bottom of the ocean complete with all the filth both inside and outside that you can imagine. And, unbelievably, it fired right up even though I couldn't really even move the power rocker switch all the way because of the filth and crap that had accumulated around it on the inside. But once all the dirt was removed, Atari's robust design sprang right back to life and the machine looks factory fresh inside and out. Third, this forum and community of enthusiasts are the best. The amount of arcane knowledge that you guys possess is impressive and really allows this hobby to feel like a shared passion. So thanks to everyone. She passes all RAM tests and SALT tests. If she continues to work reliably, I may pop a Newell FastChip in her next.

Thank you to everyone. You are all helping me to move along on this challenge. ClausB, particular thanks to you for guiding me down new paths to test. And thanks to ACML for the schematic. Thanks to Keatah for the laugh. I have a couple of definite updates: To address ClausB's ideas: 1) Z103 pin is well connected to ground, i.e. it has 0 Ohms. 2) I was WRONG on keyboard pins 1-8 as ClausB predicted. My meter was reading in mV and I didn't notice the auto-switching from the V readings on the other pins. So 1-8 are near 0 and the others are very near 4.8V so all good to go. 3) ClausB's brilliant idea to touch motherboard keyboard pins together with a simple wire yielded great results: lots of healthy 800 speaker clicks with lots of random keystrokes appearing for the first time (for me anyway) in Memo Pad. Upper, lower, inverse, space, click click click. However, a known working keyboard yields nothing but BREAK as usual. How is this even possible? Isn't the keyboard just creating shorts as well?Arg! INTERESTING FIND: I found a large discrepancy between resistance output from Z103 ground and R128 on the troubled motherboard and a known working motherboard. Here are the details: Known working motherboard: Z103 PIN 3 TO R128 northside lead (closer to cart slots) 93.7 K-OHMS Z103 PIN 3 TO R128 southside lead (closer to joysticks) 48.3 K-OHMS Troubled motherboard: Z103 PIN 3 TO R128 northside lead (closer to cart slots) .89 M-OHMS Z103 PIN 3 TO R128 southside lead (closer to joysticks) .82 M-OHMS Note the swap to mega Ohms from Kilo Ohms. I assume this may the the core of the problem somehow? If so, why would shorting keyboard pins together still produce characters? HAL 9000: My mind is going. I can feel it. Thanks to anyone who can help.

I MAY have found something but need advice. If you can follow the thread above and read the progress below and know something, please let me know! 1) POKEY pin 17 is +5V 2) Both 4051's show +5V on pin 16 3) R128 has a perfect 47K Ohm across itself 4) Grounds and +5's between POKEY and both 4051's all have continuity with 0 Ohms. Here is where I found a discrepancy. R128 runs north/south with the joystick ports pointed at you, just to the right of POKEY. 5) POKEY pin 25 (KR1) shows a connection to R128 this way: north side of resistor 0 Ohms, sound side (closer to joysticks) 46.9K Ohms 6) POKEY pin 16 (KR2) shows a connection to R128 this way: north side of resistor 94.7K Ohms, sound side (closer to joysticks) 47.6K Ohms I don't know if this is normal? A further discrepancy: 7) Z104 (the right-most 4015) pin 3 shows 0 Ohms on the north side of R128 and 46.9K Ohms on the south side 8 ) Z103 (the left-most 4015) pin 3 shows 61.6K Ohms on the north side of R128 and 12.84K Ohms on the south side Further info. All long motherboard keyboard pins tested left to right (1 to 18?) while powered and keyboard disconnected. I don't know what these values should be but I think it is normal for 18 to have 0v. No? Pin 1 = 12.1v Pin 2 = 13v Pin 3 = 12.9v Pin 4 = 13v Pin 5 = 12.5v Pin 6 = 12.5v Pin 7 = 11.5v Pin 8 = 11.2v Pin 9 = 4.97v Pin 10 = 4.75v Pin 11 = 4.77v Pin 12 = 4.77v Pin 13 = 4.79v Pin 14 = 4.8v Pin 15 = 4.79v Pin 16 = 4.75v Pin 17 = 4.79v Pin 18 = 0v

Thank you ClausB. The machine fired up untouched and still dirty with the keyboard issue the first time I opened it out of the box. I did wash the motherboard but with no change in functionality. However, some bit of hidden dirt could have been there the entire time. The motherboard looks very clean indeed but of course that means nothing. I believe I can follow your advise above. I won't be at the machine again until Monday. The only thing I'm not clear on is the "Vcc" nomenclature. What motherboard structure are you referring to? Another chip or a set of lines or the connector itself? Thanks to everyone giving this great advise! I will update you all when I know more. I feel like this is becoming an entire community helping to revive this old girl!

That's a great suggestion. I'll try to see if I can trace pin by pin from the connector back through the motherboard to see if I can find something wrong.

No joy. The POKEY transplant from the 400 to the 800 yielded nothing. Same dead keyboard with only BREAK working. So the issue is somewhere not related to 1) the keyboard, 2) the 4051's nor 3) POKEY. I'm lost.

Kyle22, you've been very helpful. I'll try the 400's POKEY and see what happens.

Arg! I swapped in two 4051's from a working donor A400 to no avail! So, I've swapped a known working keyboard and known working 4051's with the same results (the 400 was fine): every key dead except BREAK. Others may be working such as SHIFT and CTRL but I can't tell without another key working to confirm. POKEY seems great (plays music, sounds fine, etc.). Is it possible that part of POKEY could fail or should I be looking for something else on the motherboard? A blown resistor or capacitor? I found this user with the EXACT same problem but no final solution is ever discussed on the thread: http://forum.digitpress.com/forum/showthread.php?143398-Atari-800-Keyboard-issue Since this thread was from 5 years ago and he last posted 3 years ago, I'm not sure I can contact him any longer for an answer. Thanks to anyone in advance for any help you can provide!

Thanks Kyle22. I have two on order. It's amazing how this 800 cleaned up. It's actually one of the nicest machines I've come across whereas before it looked like something rats had been living in for decades. What a change. I'd really like to bring it fully back to life.

Thanks, Kyle22 and David_P! I located the pair of 4051's and swapped them. I also pulled POKEY up and sat it back down. All pins were shiny clean, sockets clean, etc. All three chips went down nice and crunchy and were a tight fit. And...nothing. No change. So perhaps I'll order a pair of 4051's and see if they are both blown for some reason...? Are all 4051's created equal or does the 48K 800 use a particular type? Several have different 2 letter prefixes...?

Kyle22, I'll try that. I know where POKEY is, but I don't know where the 4051's are offhand. I'll search online. If you know a schematic link, please let me know. Thank you!

Ok, I've got a bit deeper and here's what I've learned (I've sprayed the hell out of the switches with contact cleaner and they look great...but...?). Popping off the keycaps, you can access the little gold "claws" that close when the key/switch is pressed. Using a multimeter and leaving the claws separated (key not pressed), you can touch the positive side of a multimeter to the right claw and the negative side to the left claw. Doing this key by key gives a voltage reading on the multimeter of between 4.2 and 4.4 DC Volts. I don't know if this is normal but it's fairly consistent. ALL of the keys register this voltage EXCEPT 6, 7, Y, U and N. These five keys are "dead" -- no voltage touching the "claws." Despite ALMOST all of the other keys showing 4.2 - 4.4 DCV, only BREAK continues to work perfectly. Everything else is dead. Well, at least this is more information. I'm not sure what to do with it. Help!? Thank you!

I've acquired what I would almost literally call a "barn find" 800. The poor thing was the filthiest computer I've ever encountered and I've seen quite a few. The inside was so crusty with crap that the power switch had something partially blocking it from switching on. Once I rattled that out of the way, the machine powered up perfectly to an incredibly clean and stable Memo Pad. The outside was no better with filth ground into it. The only working key was the BREAK Key which was 100% functional. The entire rest of the keyboard was 100% non-functional. Not even an intermittent click. RESET, OPTION and SELECT work too but alas START seems to be sleeping (tested using a Pac Man cart). This 800 turned out to be a sort of "diamond in the rough" since after a FULL disassembly, a toothbrush, hot soapy water, a miracle sponge, etc. it looks almost new from '82! No cracks, scrapes, gouges not even discoloration! I think it was kept in a very, very dirty but very dark place. Here's the problem: I gave the keyboard (a Hi-Tek) a full keys-off wash and clean along with everything else. I fully expected it to come to life but no luck. The exact behavior as before. I checked all of the traces for continuity (everything seems connected) but it refuses to do anything. I know about the hitting keys over and over to get them to reconnect but I'm not sure that is the problem here since I cleaned just about everything including spraying contact cleaner on each of the little gold claws beneath the keys. BREAK, RESET, OPTION and SELECT continue to work and everything else is still dead. I don't think it's POKEY as the computer plays games great, the sound it great, etc. I know that the console keys are on a separate circuit to I will have to deal with the START key separately when or if I get the main keys working. The only keyboard matrix layout I can find applies to the 800XL, not the 800. And I cannot find anything that discusses the keyboard pin connector layout (the rainbow one in this case) that connects right under the 800's keyboard to the motherboard. Am I missing something here? Does anyone have any advise on what this might be? I feel as if I'm missing something very simple here. Thank you!

These mods are fun. It's interesting to see the increased speed via optimization, etc. JamesD, I think there's a typo in your A2E code: Line: 130 HGR2:COLOR 3 Should be: 130 HGR2:HCOLOR=3 Does anyone have a TI-99/4a Extended BASIC version worked out?

The only one that comes to mind is the purposeful code that Mattel inserted into the Intellivision II's EXEC to cause Coleco's (mostly) crappy titles from playing. It accidentally nuked Mattel's own "Word Fun" on the system and, of course, didn't last long as Coleco and others quickly figured it out and worked around it.

How about: Joust (any version) the "unbeatable?" pterodactyl. Bite me. Seaquest (Atari 2600) that bastard sub at the top of the screen. Stampede (Atari 2600, Intellivision) the "black cow." Donkey Kong (any version) fireballs my friends, fireballs. Pole Position (most versions) Road Signs. Tail of Beta Lyrae (Atari 800) magnetic satellites. Demon Attack (Intellivision) damn swooping birds on boss level. Ice Trek (Intellivision) f*cking floating icebergs. Shark! Shark! (Intellivision) the b*stard it's named after. Space Armada (Intellivision) two unavoidable words: invisible. aliens.

Amdex Color 300 with Chroma/Luminance separation (S-video). Bought new in the 1980's still crystal clear with saturated colors to this day. No burn-in thanks to Atari 800's built in color shifting.

Oh good grief! Talk about feeling like an idiot. I've been playing this game exclusively on the highest level for so many years that I never realized that the numbers and islands CHANGE COLOR depending on what level you're playing. Ok, idiot posting, move on, nothing to see here.

I can't find any information about a ROM variant for Sub Hunt other than "No ROM variants have been identified" at INTV Funhouse. However, I've recently noticed that I have two Sub Hunt red label carts that are *clearly* different. One of them has the "upper land mass" -- the place the enemy ships are headed -- AND the number of ships sunk indicator on the left shown in RED. This is a common screen shot and is the image on the standard box art I believe. However, my other Sub Hunt has the "upper land mass" shown in black and the number of ships sunk counter is also in black. Interestingly, this "black" version seems *harder* to win, at least on the Admiral level. I'll need to really test this theory more but the destroyers seem more aggressive in this version. Am I missing something here? Is this a well known ROM variant, say Mattel / Sears or something that I've never heard about or noticed? Did Mattel update the ROM during the run of this game?

Absolutely! 1 set.